Author(s): Shu Kai Ng; Akihiko Nakayama; Wei Xuan Ng; Tatsuhiko Uchida

Linked Author(s): Akihiko Nakayama, Tatsuhiko Uchida, Shu Kai Ng

Keywords: Small hydropower; Smoothed Particle Hydrodynamics (SPH); Gravitational Vortex Turbine (GVT); Fluid-Structure Interaction (FSI); Scaled-model validation

Abstract: The analysis of the flow through small hydropower is important for optimal design. The flow is neither that of internal conduit nor an open-channel flow. The air mixes with the water and the water droplets can separate from the main body of water flow. The turbine moves in the complex two-phase flow. Conventional Computational Fluid Dynamics (CFD) methods cannot deal with such flows that have a violent free surface motion and complex geometric boundaries or obstructions where the violent free surface flow interacts with the moving blades of a water turbine. In the present work, numerical analysis with Smoothed Particle Hydrodynamics (SPH) simulation and experimental observation in a laboratory have been conducted to examine the properties of the flow in a basic configuration of a gravitational vortex turbine (GVT). The numerical simulation models the flow and motion of the turbine due to the given inflow and elevation drop. It is a Weakly Compressible SPH method (WCSPH) with improved boundary conditions on the curved and moving body. In the experiment, the motion of the flow and the rotation of the turbine are recorded by a video camera. Furthermore, the torque and load on the turbine are measured simultaneously. It is found that the SPH simulation approximately reproduces the qualitative features of the flow and the dynamics of the turbine. Although more validation runs need to be made, it is found that the method can be further refined to identify the optimal configuration and installation method in the small streams of Malaysia.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0906-cd

Year: 2023